4971(e) Liability for Tax.—
4971(e)(1) In general.—
Except as provided in paragraph (2), the tax imposed by subsection (a), (b), or (f) shall be paid by the employer responsible for contributing to or under the plan the amount described in section 412(a)(2).
(Code Sec. 4971(e)(2), below, was amended by P.L. 109-280. For sunset provision, see P.L. 109-280, §221(c).) _
4971(e)(2) Joint and several liability where employer member of controlled group.—
4971(e)(2)(A) In general.—
If an employer referred to in paragraph (1) is a member of a controlled group, each member of such group shall be jointly and severally liable for the tax imposed by subsection (a), (b), (f), or (g).
4971(e)(2)(B) Controlled group.—
For purposes of subparagraph (A), the term “controlled group” means any group treated as a single employer under subsection (b), (c), (m), or (o) of section 414.